Grinding machine



Oct. 17, 1939. R. H. CRAMER 2,176,243

GRINDING MACHINE Filed June 16, 1956 5 Sheets-Sheet 1 R. H. CRAMER GRINDING MACHINE Oct. 17, 1939.

Filed June 16, 1936 5 Sheets-Sheet 2 mt M 1 wfi hfi 0% i L WIMP. WW I I Q2 $8 NE O NH wmw H/SA raw/v5 x Patented Oct. 17,1939

UNITED STATES I PATENT OFFICE GRINDING MACHINE Raymond 11. Cramer, 1am, N. 1., assilnor to General Motors Corporation, Detroit, Mich a corporation of Delaware Application June 16, 1936. Serial No. $5,540

1': Claims. (01. 51-238) 7 This invention relates to grinding machines to conform to the concave raceway surface of a and methods and comprises all of the features race ring R or similar hollow work piece. The and aspects of novelty herein disclosed. An ring it constitutes a regulating wheel which conobject of the invention is to provide a precision trols the rotation of the race ring R while the grinding machine for grinding the bore of a latter is internally ground by a grinding wheel G hollow work-piece concentric with a contoured which is indicated by broken lines. The wheel G or tapered peripheral surface, said bore also beis adapted to be reciprocated and to be fed horiing ground perpendicular to the ends of the zontally against the bore of the race ring at a piece. Another object is to provide improved point directly opposite to the surface 30. As will 1. means for preventing endwise shifting of a workappear there are two other work-supporting 1( piece during grinding with provision for accuratewheels or flanges engaging the raceway surface ly locating the piece endwise especially when the and a thrust member which engages the end surpiece is externally tapered or otherwise contoured. face of the race ring to resist the axial pressure Another object is to provide improved means of the race ring induced by the angular disposill for gauging the bore of a hollow work-piece, tionof the contoured engaging surfaces. discharging grit from the piece, and shielding Projecting upwardly from the head It are the bearings for the gauge and the end thrust standards 38 carrying a bracket 40 in which a member. Another object is to provide improved rock shaft 42 is journalled for rocking movement. work supporting wheels which have replaceable Projecting forwardly from the rock shaft is a work engaging surlfaces for contoured workpair of arms 44 and 45 connected together by pieces. Still another object is to provide an ima housing 45 which encloses a flange or work proved method of grinding the bore of a hollow engaging ring having a convex surface 52 conwork-piece whose outer periphery is tapered or forming to the raceway surface. As shown in contoured. Figure 5 the ring 56 abuts at one end against To these ends and also to improve generally a shoulder 54 on a hub sleeve 56, a nut 58 deupon devices of this character, the invention tachably holding the ring on the sleeve. The 2:

consistsin the various matters hereinafter desleeve is journalled for rotation on a pair of scribed and claimed. In its broader aspects, the spaced bali bearings of diiferent sizes. The larger invention is not necessarily limited to the specific bearing 60 has its outer race ring engaging an a construction selected for illustrative purposes in internal shoulder in the hub sleeve and held the accompanying drawings in which: therein by washers G2 backed up by a ring nut Fig. 1 is a plan view of the machine, some 6. The inner race ring of the bearing is held parts being broken away and shown in axial by washers 66 backed up by a nut 68 on an inner section and the upper idler wheel being removed. sleeve 10. The washers F52 and 66 have thin Fig. 2 is a front elevation of the head which flanges which interfit with one another to form supports the gauge and the thrust member, a a labyrinth seal. 'The inner race ring of the portion of the base being broken away and in bearing 68 is clamped against a spacing sleeve 12 section. i which abuts against the inner race ring of a Fig. 3 is a cross section on line 3-3 of Fig. 2. second ball bearing M, the inner race ring abut- Fig. 4 is an end elevation of the machine. ting at one end against washers it which engage 4 Fig. 5 is an enlarged sectional view of the a flange I8 on the inner sleeve ill. The outer mounting for the upper idler wheel. race ring of the bearing is is slidably mounted in The numeral l0 indicates a base plate having the hub sleeve and the latter is closed by washers pads to which are screwed projecting lugs or clamped against an internal shoulder by a i'eet I! on a head II which forms a journal supring nut 82. The washers l8 and 80 have inter- 4 port for a rotary spindle i! The spindle has a. fitting flanges to form a labyrinthseal. driving pulley I! at one end and its other end The outer race ring of the bearing M is' urged is tapered to detachably receive a hub 20 fastened axially by spring pressure to preload the bearings Y to the spindle by a circular clamping plate or and prevent play. A thick slidable ring 8 ena washer 22 and a screw bolt 24. The hub 20 is. gages the outer race ring and is provided .with externally recessed at its outer end to provide a. series of axial sockets for coil springs which a shouldered seat for a flange or work engaging also engage a series of sockets in a ring 88 which ring 26 which is fastened to the hub by screw abuts against the outer race ring of the larger bolts 23. The periphery of the ring 26 is tapered, bearing 60; In order to limit the tendency to preferably being, transversely convex as at 30 separate the bearings, as when the latter are removed from the hub sleeve, screws 90 are threaded in the ring 84 and are slidable in the ring 88, the heads of the screws being contained in recesses of the ring 88 and acting as stops.

The inner sleeve is supported by a shaft 92 having at one end a ball segment 94 contained in co-operating v socket plates 95 and 98, the

former being flanged and engaging an opening in the arm 45 and the socket plate 98 being 10 threaded into the socket plate 96. At the other end, the shaft 92 has a thimble I00 secured by a screw. I02. The thimble has clearance in an opening of the arm 44 and its opposite sides are flattened and engaged by set screws I04 which I are arranged in pairs and radially mounted in the arm. By means of the screws I04 the'shaft 92 and the hub sleeve can be tilted with respect to the other wheels so that, when thehub sleeve carries acylindrical wheel or roller, cylindrical work will be urged in an axial direction against a thrust plate. In use, the work engaging ring 50 is pressed downwardly by a suitable spring to urge the work piece against the regulating wheel and a supporting idler wheel which will now be 5, described.

A flange or work engaging ring I I0 is detachably held by a ring nut II2 against an external shoulder on a hub sleeve II4. This hub sleeve is joumalled for rotation in antifriction bearings which are preferably constructed in the same way as the bearings shown in Fig. 5 for the work engaging ring 50. The inner sleeve 10, however, instead of being mounted on a through shaft such as 92 in Fig. 5, is mounted upon a pair of individual stub shafts II5 projecting towards one another from half round sockets H1 in a pair of spaced standards H8. ,The outer end portions of the studs are slabbed oil? 'or flattened at one side and clamped inadjusted positionto the standards by bolts H9. The heads of screws I20 overlap the ends of the shafts and provide for adjusting the flange IIO into accurate alignment with the other work-engaging flanges 25 and 50. By the foregoing construction the bolts' I I9 may be removed to permit removal of the work engaging ring IIO, hub sleeve H4 and its e'ntire bearing structure without disturbing those bearings. The standards 8 are carried bya slide I22 having ways I24 (Fig. 4) slidable on inelined ways I25 carried by the base plate I0. The slide has a tongue provided with a tapped opening for an adjusting screw I28 which is journalled for rotation without endwise movement in a plate I 30. attached to the front of the base plate I0, the screw being turned by a hand wheel I82.- To firmly I hold the slide in position after it has been :ad-

.iusted, a side clamping plate I34 has a'lip which is forcedagalnst a bevelled side of the slide by a bolt I The machine also carries a supporting structlu'e havinga gauge and a thrust plate which is provided with a thrust bearing to resist the axial component of pressureexerted on the contouredthe gauge will line up axially with the bore of the work piece, one end of the swivel plate has a lug I45 projecting between a pair of upright studs I48 carrying adjusting'screws I50 engag- 1; ing opposite sides of the lug. Fastened by screws to the swivel plate is a supporting plate I52 having dove-tailed ways for a cross slide 154 which is adjustable from front to rear by a screw I55 threaded in the cross slide and journalled for rotation without endwise movement in a vertical plate I58 attached to the front of the supporting plate I52. The slide I54 carries a gauge head I55 inwhich a sleeve and a gauge rod are mounted for rotation, the gauge rod also being reciprocated in the sleeve. The cross slide adjusts the gauge head into concentricity with the work.

Within each end of the head I50 is a raceway sleeve I52 and an end ring I54, a ring nut I55 being threaded in the head against the raceway sleeve and serving as the end. ring for a series of antifriction bearing rollers I68. J ournalled for rotation in these bearings is a spindle in. the form of a sleeve I10 having one end provided with a threaded portion receiving a hollow thrust mem ber I12 having an inwardly projecting stop flange I14. The thrust member has holes I15 to facilitate cooling and removal of sludge by centrifugal action. It carries a skirt or shield I15 surrounding the adjacent endof the head I 50 while its outer end carries a thrust ring I18 detachably secured thereto by screws. The thrust ring has a tapered annular flange I19 with anabutment face which is ground perpendicular to its axis and is adapted. to engage the end face of the raceway sleeve R to prevent axial movement of the race ring. A shield I has an axially projecting flange engaging the interior of the stop flange I14 and abutting at its end against a bearing sleeve I82 in a counterbore ofthe rotary sleeve I10. Slidably mounted in the bearing sleeve I82 3 is a hollow gauge rod I84 at the inner end of which is a plate I85 having an axially projecting shield or skirt I88 overlapping the shield I85. The shield enters the thrust member and termin/ates in a flange to sling coolant through the 1m openings I15. Next tothe plate I85 is a pair of M gauges I90 held by a hollow, headed screw I92 threaded in the end of the rod and clamping the gauges and the plate I85 to the end of therod. These gauges difler slightly in their external dlmansions and are adapted tosuccessively enter" the bore of the race ring as the latter is being internally ground, the gauges being intermittently thrust against the end of the piece during the grinding operation and controlling the grinding operation when they enter the work in a manner well understood in the art. Cooling fluid enters the work through the gauge rod and the hollow screw and carries the sludge out through the openings I-1-5 by centrifugal action, thus protecting the bearing I82 and preventing the sludge from packing behind the gauges. The. other end of the rotary sleeve I10 has a bearing 200 for the gauge rodI84 on which a hub member 202 is fastened by a set screw 204.

The hub member carries a flange or shield 255 and is held for rotation with the sleeve I10 by a rod 208 carried by the hub and projecting into an axial hole in the sleeve, the rodbeing freely slidable in the hole to allow sliding of the gauge rod. Threaded on the exterior of the head I50 is an adjusting nut or sleeve 2I0 having an internal flange 2I2 next to a thrust ring 2I4 of a ball thrust bearing 2I5. An opposed thrust ring 2I8 is clamped against a shoulder in the sleeve 70 2I0 by 'a ring nut 220/ The thrust ring -2I4 is clamped against a shoulder of the rotary sleeve I10 by an axially projecting flange on a nut 222. Thus the end thrust of the work piece against the thrust ring I18 is transmitted through the spin- 1;

threaded sleeve 2 l 0' and protects the thrust bearing.

On the top of the head ISO is an oil cup 230 to provide for lubrication of the bearings I68, holes 23l in the sleeve H0 conducting oil to hearing sleeves I82 and 200. A locking pin 232 is adapted to be projected radially into a hole 234 (Fig. 3) to lock the rotary sleeve I against rotation' as when applying or removing the threaded thrust sleeve I12. The locking pin carriesa little latch pin 236 normally engaging shallow recesses in a pair of lugs 238 projecting upwardly from the head. A knob 24!] is secured to the upper end of the locking pin whereby the latter may be elevated to remove the little latch pin 236 from its recess in the lugs and turned 90 so that the latch pin..will enter a cross recess 242 between the lugs,

thus letting the locking pin down into the hole or contour desired for the work by suitable dress ing mechanism and placed on the wheel spindle. It is then fed against the flange or ring 26 to shape the latter. The lower flange or ring Ill) which can belmoved up to the grinding wheel by the inclined slide I22 is then ground by feeding the grinding wheel rearwardly. Then the upper work supporting flange or ring 50 is swung down and similarly ground. The face I of the thrust ring I18 is ground flat and perpendicular to its axis of rotation by the end of the grinding wheel, the swivel plate I40 providing for adiustment of this axis into parallelism with the other axes. This truing of all the work engaging members on the machine at one setting insures a perfect setup for concentricity, squareness and alignment in grinding the bore of the race ring R. or other contoured work-piece. For work-pieces which have a different contour, the work-engaging rings or flanges 26, 50, and III! are readily removable for replacement by others all without disturbing the hub structure or their alignment.

In operation, the race ring R. is rotatably supported with its contoured surface against the three rings or flanges, the end of therace ring abutting against the face I19 which takes the reaction or endwise component of pressure due to the inclination of the contoured surfaces. This face'is accurately adjusted endwise of the work by the threaded sleeve 2) which controls the position of the thrust bearing 216 and the sleeve H0. The work is'thus accurately located and when the grinding wheel R is fed against the bore and reciprocate'd therein, the bore is ground concentric with its periphery and perpendicular to the ends of the work. I

Iclaim: a

-1. In a machine of the character described, means for supporting and rotating a round workpiece, an end thrust member adapted to engage one end of the work-piece to locatethe latter axially and to resist endwise movement thereof,

journal bearings for rotatably supporting the end thrust member, a thrust bearing for preventing endwise movement of the end thrust member,

a head for supporting said end thrust member and its bearings independently of said work supporting and rotating means, and means for axially shifting the thrust bearing and the end thrust member with respect to said head; substantially as described.

2. In a machine of the character described, means for supporting and rotating a round workpiece, a head, a rotatable hollow spindle journalled in the head and having an end thrust member adapted to engage one end of the work piece to resist endwise movement thereof, a thrust bearing reacting between the spindle and the head, and means for shifting the spindle and its thrust bearing axially with respect to the head; substantially as described.

3. In a machine of the character described, means for supporting and rotating a round workpiece, a head having journal bearings, a rotatable spindle journalled in the bearings and adapted to shift axially therein, the spindle having a thrust member at one end adapted to engage theend of the work-piece, the head having an adjusting member threaded thereto, and an antifriction thrust bearing housed in the adjusting member and reacting between the adjusting member and the other end of the spindle; substantially as described.

4. In a machine of the character described, means for supporting and rotating a hollow work-piece, a head, a rotatable sleeve iournalled in the head independently of the supporting and rotating means and having an end thrust member adapted to engage one end of the'work-piece, a thrust bearing reacting between the sleeve and the head, a rod slidable in the sleeve, and a hub member on the rod and having a flange overlapping the thrust bearing; substantially as described.

5. In a machine of the character described, means for supporting and rotating a hollow workpiece, a rotatable sleeve mounted independently of the supporting and rotating means and carrying an end thrust member adapted to engage one end of the work-piece, a gauge rod slidably mounted in the sleeve and having a gauge adapted to enter the work piece, a hub member secured to the gauge rod at one end of the sleeve, 9. pin

' carried by one of the last named parts and entering axially into a hole in the other part, and the hub member having a shield projecting around the sleeve; substantially as described.

6. In a machine of the character described, wheels for peripherally supporting and rotating a hollowwork-piece, a hollow end thrust member adapted to engage one end of the work-piece, means for conducting coolant to the interior of the work-piece, and said end thrust member having openings to discharge the coolant; substantially as described.

a hollow work-piece, a rotatable sleeve having a hollow end thrust member adapted to engage one end of the work-piece, the thrust member having openings, a hollow rod extending through the sleeve to conduct coolant to the interior of the work-piece, and a shield carried by the rod and entering the hollow thrust member; substantially as described.

as described.

9. In a machine or the character described, wheels tor peripherally supporting and. rotating a hollow work-piece, a rotatable sleeve having a hollow end thrust member adapted to engage one end of the work-piece, the thrust member having end or the work-piece, the thrust member having openings, a gauge rod extending through the sleeve and having a gauge adapted to enter the work-piece, means for conducting coolant to the interior of the work-piece, and a plate carried by the gauge rod and having a shield entering thehollow thrust member; substantially as described.

.11. In a machine of the character described, wheels for peripherally supporting and rotating a hollow work-piece, a'rotatable sleeve having an end thrust member adapted to engage one end of the work-piece, a head having bearings for rotatably supporting the sleeve. and a gauge rod slid ably mounted in the sleeve and having a gauge adapted to enter the work-piece; substantially v12. In a machine oi the character described, wheels mounted to rotate on parallel axes to pcripherally support and rotate a round work-piece,

an end thrust member adapted to engage the end 01' the work-piece, a swivel plate having means to rotatably support the end thrust member, and means tor-swivelling the plate to locate the axis of the end thrust member with respect to the wheel axes; substantially as described.

l3. In a machine of the character described,

wheels mounted to rotate on parallel axes to peripherally support and rotate a round work-piece,

- an end thrust member adapted to engage the end of the work-piece, a head having bearings for rotatably supporting the end thrust member. a swivelling support for the head, and means for angularly adjusting the support to locate said hearings in, parallelism with the axes or the wheels; substantially as described.

14. In agmachine of the character described, means for rotatably supporting a round workpiece and comprising a plurality of wheels and an end thrust member, the wheels and the thrust member being rotatable on parallel axes and the wheels being spaced angularly about a central work receiving space, and the peripheries of the wheels converging in one direction to urge the work-piece against the thrust member; substantially as described.

15. In a machine of the character described, a work head comprising a plurality of angularly spaced'work supportingsurfaces which incline with respect to a central axis to exert radial and axial pressure against the similarly inclined periphery of a work-piece interposed between them, and a thrust member rotatable in line with said axis and engaging the endo! the work-piece to prevent axial movement thereof; substantially as described.

16. In a machine oi! the character described, a work head comprising a plurality ,of rotatable wheels angularly spaced about an axis and having their peripheral surfaces inclined to said axis to form a tapered work-receiving space for an externally tapered work-piece, a spindle rotatable in line with said axis, and a thrust member carried by the spindle and having a thrust lace normal to said axis to engage the end of the workpiece to hold the latter in contact with the wheels; substantially as described.

- 17. In a machine of the character described, a

work-head comprising a plurality ofhub members rotatable about parallel axes, the hub members having external seats, and flanges secured on said seats and-having peripheral surfaces which are similarly contoured an'd inclined with respect to said axes; substantially as described.

RAYMOND H. CRAMER. 

